Check BR1 And Br2 on the driver board,To test with meter set it diode setting set black probe on "oddball" leg this is the one that is out of the "square"
Place red probe adjacent legs..4 - .7 should be on the reading.

Place red probe on leg catecorner from "oddball" leg.
Place black probe on the adjacent legs. .4 - .7 should be on the reading

you may see "short", which is a clear indication of a failed bridge.

Check capacitors also,With meter set to ohms setting.
if the ohms steadily climb it's good,There's a +/- on the capacitor, - will have a stripe on it.If numbers on meter don't climb it's a bad capacitor.